<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
       @click-left="onClickLeft"
      title="头条"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap" v-if="loading">
        <van-loading
          color="#3296fa"
          vertical
        >加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail" v-else-if="article.data.title">
        <!-- 文章标题 -->
        <h1 class="article-title">{{article.data.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <template #icon>
          <van-image
            class="avatar"
            round
            fit="cover"
            :src="article.data.aut_photo"
          />
          </template>
          <template #title>
          <div class="user-name">{{article.data.aut_name}}</div>
          </template>
          <template #label>
          <div class="publish-date">{{dayjs().to(dayjs(article.data.pubdate))}}</div>
          </template>
        <!-- 关注按钮 -->
          <FollowUser
          class="follow-btn"
          :is-followed="article.data.is_followed"
          :user-id="article.data.aut_id"
          @deleteFollow='article.data.is_followed = false'
          @addFollow='article.data.is_followed = true'
          ></FollowUser>
        <!-- /关注按钮 -->
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div class="article-content markdown-body" v-html="article.data.content" ref="article-content"></div>
        <van-divider>正文结束</van-divider>

        <!-- 评论列表 -->
        <CommentList
        :source='article.data.art_id'
        :list="commentList"
        @onload-success='onloadSuccess'
        @reply-click="onReplyClick"
        ></CommentList>
        <!-- /评论列表 -->

         <!-- 底部区域 -->
    <div class="article-bottom">
      <van-button
        class="comment-btn"
        type="default"
        round
        size="small"
        @click="show=true"
      >写评论</van-button>
      <van-icon
        name="comment-o"
        :badge="totalCommentCount"
        color="#777"
      />
      <!-- 收藏按钮 -->
      <CollectArticle
      :isCollected='article.data.is_collected'
      :articleId='article.data.art_id'
      @addCollect='article.data.is_collected=true'
      @deleteCollect='article.data.is_collected=false'
      ></CollectArticle>
      <!-- /收藏按钮 -->

      <!-- 点赞按钮 -->
      <LikeArticle
      :isLiked='article.data.attitude'
      :articleId='article.data.art_id'
      @addLike='article.data.attitude=1'
      @deleteLike='article.data.attitude=-1'
      ></LikeArticle>
      <!-- /点赞按钮 -->
      <van-icon name="share" color="#777777"></van-icon>
    </div>
    <!-- /底部区域 -->

    <!-- 发布评论 -->
    <van-popup v-model:show="show" position="bottom">
    <CommentPost
    :target='article.data.art_id'
    @post-success="onPostSuccess"
    ></CommentPost>
    </van-popup>
    <!-- /发布评论 -->
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap" v-else-if="errStatus===404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div class="error-wrap" v-else>
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn" @click="loadArticle">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 评论回复，用v-if销毁内容残存是神来之笔 -->
    <van-popup v-model:show="isReplyShow" position="bottom" :style="{ height: '100%' }">
    <CommentReply
    v-if="isReplyShow"
    :comment="currentComment"
    @close="isReplyShow=false"
    @onPostSuccess="currentComment.reply_count++"
    ></CommentReply>
    </van-popup>
    <!-- /评论回复 -->
  </div>
</template>

<script>
import { getArticleById } from '@/api/article'
import { reactive, ref } from '@vue/reactivity'
import { getCurrentInstance, provide } from 'vue'
import { ImagePreview } from 'vant'
import FollowUser from '@/components/follow-user/index.vue'
import CollectArticle from '@/components/collect-article/index.vue'
import LikeArticle from '@/components/like-article/index.vue'
import CommentList from '@/views/article/components/comment-list.vue'
import CommentPost from '@/views/article/components/comment-post.vue'
import CommentReply from '@/views/article/components/comment-reply.vue'
import router from '@/router/index'
import dayjs from 'dayjs'
export default {
  name: 'ArticleIndex',
  props: {
    articleId: {
      type: [Number, String],
      required: true
    }
  },
  created () { this.loadArticle() },
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  setup (props) {
    provide('articleId', props.articleId)// 给所有的后带组件提供数据
    const { proxy } = getCurrentInstance()
    const article = reactive({ data: {} })
    const loading = ref(false)// 加载状态
    const errStatus = ref(0)// 失败状态码
    const totalCommentCount = ref(0)// 评论小红点
    const show = ref(false)// 发布评论是否显示
    const isReplyShow = ref(false)// 评论回复是否显示
    const commentList = ref([])// 腾转挪移之评论列表
    const currentComment = ref({})// 当前点击回复的评论项
    async function loadArticle () {
      loading.value = true
      try {
        const { data } = await getArticleById(props.articleId)
        article.data = data.data
        // 初始化图片点击预览，放入异步以保证获取dom元素
        setTimeout(() => {
          previewImage()
        }, 0)
      } catch (err) {
        if (err.response && err.response.status === 404) {
          errStatus.value = 404
        }
      }
      loading.value = false
    }
    function onClickLeft () {
      router.go(-1)
    }
    function previewImage () {
      const articleContent = proxy.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')// 获取所有图片对象
      const images = []
      imgs.forEach((img, index) => {
        images.push(img.src)
        img.onclick = function () {
          ImagePreview({
            images, // 预览图片地址数组
            startPosition: index// 预览起始图
          })
        }
      })
    }
    // 渲染评论
    function onloadSuccess (data) {
      const { results } = data
      commentList.value.push(...results)// 评论列表
      totalCommentCount.value = data.total_count// 红点
    }
    // 发布评论
    function onPostSuccess (data) {
      show.value = false
      commentList.value.unshift(data.new_obj)
      totalCommentCount.value++
    }
    // 点击了评论回复
    function onReplyClick (comment) {
      isReplyShow.value = true
      currentComment.value = comment
    }

    return {
      article,
      dayjs,
      loading,
      errStatus,
      totalCommentCount,
      show,
      isReplyShow,
      commentList,
      currentComment,
      loadArticle,
      onClickLeft,
      onloadSuccess,
      onPostSuccess,
      onReplyClick
    }
  }

}
</script>

<style scoped lang="less">
@import './github-markdown';// css组件在style里用@import引入，记得';'

.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
